Reviewers: Sven Panne,
Message:
PTAL
Description:
[x64] Improve instruction selection for TruncateInt64ToInt32.
Please review this at https://codereview.chromium.org/936323004/
Base URL: https://chromium.googlesource.com/v8/v8.git@master
Affected files (+55, -40 lines):
M src/compiler/x64/instruction-selector-x64.cc
M test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc
b/src/compiler/x64/instruction-selector-x64.cc
index
db2d8cb08c7813f944a31f5ac7c8fc98ec7fb244..0689eb9adc63c029f69af82f3426cd1a4aea6ea6
100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -812,12 +812,22 @@ void
InstructionSelector::VisitTruncateInt64ToInt32(Node* node) {
Node* value = node->InputAt(0);
if (CanCover(node, value)) {
switch (value->opcode()) {
- case IrOpcode::kWord64Sar:
- case IrOpcode::kWord64Shr: {
+ case IrOpcode::kWord64Sar: {
Int64BinopMatcher m(value);
- if (m.right().Is(32)) {
+ if (m.right().IsInRange(1, 32)) {
Emit(kX64Shr, g.DefineSameAsFirst(node),
- g.UseRegister(m.left().node()), g.TempImmediate(32));
+ g.UseRegister(m.left().node()),
+ g.UseImmediate(m.right().node()));
+ return;
+ }
+ break;
+ }
+ case IrOpcode::kWord64Shl: {
+ Int64BinopMatcher m(value);
+ if (m.right().IsInRange(1, 31)) {
+ Emit(kX64Shl32, g.DefineSameAsFirst(node),
+ g.UseRegister(m.left().node()),
+ g.UseImmediate(m.right().node()));
return;
}
break;
@@ -826,7 +836,9 @@ void
InstructionSelector::VisitTruncateInt64ToInt32(Node* node) {
break;
}
}
- Emit(kX64Movl, g.DefineAsRegister(node), g.Use(value));
+ // Otherwise truncation from 64-bit to 32-bit is a no-nop, as 32-bit
+ // operations just ignore the upper 64-bit.
+ Emit(kArchNop, g.DefineAsRegister(node), g.Use(value));
}
Index: test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
diff --git
a/test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
b/test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
index
1f374c0f856d7662cbcda5812bf556a10696ab73..e524764f828626c4d1459e2857c3b450d1987f7f
100644
--- a/test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
+++ b/test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
@@ -63,15 +63,6 @@ TEST_F(InstructionSelectorTest,
TruncateFloat64ToFloat32WithParameter) {
}
-TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithParameter) {
- StreamBuilder m(this, kMachInt32, kMachInt64);
- m.Return(m.TruncateInt64ToInt32(m.Parameter(0)));
- Stream s = m.Build();
- ASSERT_EQ(1U, s.size());
- EXPECT_EQ(kX64Movl, s[0]->arch_opcode());
-}
-
-
//
-----------------------------------------------------------------------------
// Loads and stores
@@ -206,37 +197,49 @@ INSTANTIATE_TEST_CASE_P(InstructionSelectorTest,
// TruncateInt64ToInt32.
-TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithWord64Sar) {
+TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithParameter) {
StreamBuilder m(this, kMachInt32, kMachInt64);
- Node* const p = m.Parameter(0);
- Node* const t = m.TruncateInt64ToInt32(m.Word64Sar(p,
m.Int64Constant(32)));
- m.Return(t);
+ m.Return(m.TruncateInt64ToInt32(m.Parameter(0)));
Stream s = m.Build();
- ASSERT_EQ(1U, s.size());
- EXPECT_EQ(kX64Shr, s[0]->arch_opcode());
- ASSERT_EQ(2U, s[0]->InputCount());
- EXPECT_EQ(s.ToVreg(p), s.ToVreg(s[0]->InputAt(0)));
- EXPECT_EQ(32, s.ToInt32(s[0]->InputAt(1)));
- ASSERT_EQ(1U, s[0]->OutputCount());
- EXPECT_TRUE(s.IsSameAsFirst(s[0]->OutputAt(0)));
- EXPECT_EQ(s.ToVreg(t), s.ToVreg(s[0]->OutputAt(0)));
+ ASSERT_EQ(0U, s.size());
}
-TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithWord64Shr) {
- StreamBuilder m(this, kMachInt32, kMachInt64);
- Node* const p = m.Parameter(0);
- Node* const t = m.TruncateInt64ToInt32(m.Word64Shr(p,
m.Int64Constant(32)));
- m.Return(t);
- Stream s = m.Build();
- ASSERT_EQ(1U, s.size());
- EXPECT_EQ(kX64Shr, s[0]->arch_opcode());
- ASSERT_EQ(2U, s[0]->InputCount());
- EXPECT_EQ(s.ToVreg(p), s.ToVreg(s[0]->InputAt(0)));
- EXPECT_EQ(32, s.ToInt32(s[0]->InputAt(1)));
- ASSERT_EQ(1U, s[0]->OutputCount());
- EXPECT_TRUE(s.IsSameAsFirst(s[0]->OutputAt(0)));
- EXPECT_EQ(s.ToVreg(t), s.ToVreg(s[0]->OutputAt(0)));
+TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithWord64Sar) {
+ TRACED_FORRANGE(int32_t, k, 1, 32) {
+ StreamBuilder m(this, kMachInt32, kMachInt64);
+ Node* const p = m.Parameter(0);
+ Node* const t = m.TruncateInt64ToInt32(m.Word64Sar(p,
m.Int64Constant(k)));
+ m.Return(t);
+ Stream s = m.Build();
+ ASSERT_EQ(1U, s.size());
+ EXPECT_EQ(kX64Shr, s[0]->arch_opcode());
+ ASSERT_EQ(2U, s[0]->InputCount());
+ EXPECT_EQ(s.ToVreg(p), s.ToVreg(s[0]->InputAt(0)));
+ EXPECT_EQ(k, s.ToInt32(s[0]->InputAt(1)));
+ ASSERT_EQ(1U, s[0]->OutputCount());
+ EXPECT_TRUE(s.IsSameAsFirst(s[0]->OutputAt(0)));
+ EXPECT_EQ(s.ToVreg(t), s.ToVreg(s[0]->OutputAt(0)));
+ }
+}
+
+
+TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithWord64Shl) {
+ TRACED_FORRANGE(int32_t, k, 1, 31) {
+ StreamBuilder m(this, kMachInt32, kMachInt64);
+ Node* const p = m.Parameter(0);
+ Node* const t = m.TruncateInt64ToInt32(m.Word64Shl(p,
m.Int64Constant(k)));
+ m.Return(t);
+ Stream s = m.Build();
+ ASSERT_EQ(1U, s.size());
+ EXPECT_EQ(kX64Shl32, s[0]->arch_opcode());
+ ASSERT_EQ(2U, s[0]->InputCount());
+ EXPECT_EQ(s.ToVreg(p), s.ToVreg(s[0]->InputAt(0)));
+ EXPECT_EQ(k, s.ToInt32(s[0]->InputAt(1)));
+ ASSERT_EQ(1U, s[0]->OutputCount());
+ EXPECT_TRUE(s.IsSameAsFirst(s[0]->OutputAt(0)));
+ EXPECT_EQ(s.ToVreg(t), s.ToVreg(s[0]->OutputAt(0)));
+ }
}
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